Single-crystal nitride-based semiconductor substrate and method of manufacturing high-quality nitride-based light emitting device by using the same

ABSTRACT

A nitride-based light emitting device is manufactured by using a single-crystal nitride-based semiconductor substrate. A seed material layer is deposited on a first substrate where organic residues including a natural oxide layer are removed from an upper surface of the first substrate. A multifunctional substrate is grown from the seed material layer. The single-crystal nitride-based semiconductor layer including a nitride-based buffer layer is formed on the multifunctional substrate. The seed material layer primarily assists the growth of the multifunctional substrate, which is essentially required for the growth of the single-crystal nitride-based semiconductor substrate. The multifunctional substrate is prepared in the form of a single-crystal layer or a poly-crystal layer having a hexagonal crystalline structure. The light emitting device employing the single-crystal nitride-based semiconductor substrate is used as a next-generation white light source having high capacity, large area, high brightness and high performance.

This application claims priority to Korean Patent Application No.2005-74100, filed on Aug. 12, 2005, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which in its entiretyare herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a single-crystal nitride-basedsemiconductor substrate and a method of manufacturing a vertical typenitride-based light emitting device by using the same. Moreparticularly, the present invention relates to a method of growing asingle-crystal nitride-based semiconductor substrate under hightemperature and hydrogen atmosphere by using a seed material layer(“SML”) and a multifunctional substrate (“MS”), which are sequentiallyformed on an upper surface of a first substrate (“FS”) so as to preventmechanical and thermal strain and decomposition from occurring at theupper surface of the first substrate including sapphire, silicon (Si),zinc oxide (“ZnO”) or gallium arsenide (“GaAs”). The present inventionalso relates to a high-quality nitride-based light emitting device and amanufacturing method thereof, in which the nitride-based light emittingdevice employs a single-crystal nitride-based semiconductor substrateand a light emitting structure, so that the nitride-based light emittingdevice has a large size and represents superior light efficiency andheat dissipation while being operated at a low operational voltage.

2. Description of the Related Art

With the rapid technological advance of optoelectronic devices, such asblue/green diodes, (near) infrared light emitting diodes, laser diodesand optical sensors, single-crystal nitride-based semiconductors havebecome very important materials in optical industrial fields. Ingeneral, optoelectronic devices employing the single-crystalnitride-based semiconductors are grown from the upper surface of a thickinsulating sapphire substrate or a conductive silicon carbide (“SiC”)substrate under the hydrogen atmosphere where ammonium (“NH₃”) andhydrogen (“H₂”) carrier gas are provided in a high temperature conditionof 1200° C. or more. However, since the insulating sapphire substrate orthe conductive silicon carbide substrate is expensive as compared with asilicon substrate, the insulating sapphire substrate and the conductivesilicon carbide substrate are inefficient for cost purposes. Since thenitride-based optoelectronic devices generate a large amount of heatduring the operation thereof, the substrate must dissipate the heatgenerated from the nitride-based optoelectronic devices. However, if thenitride-based optoelectronic devices are formed on the upper surface ofthe insulating sapphire substrate having a thickness of 70 micron metersor more, the insulating sapphire substrate cannot easily dissipate theheat because the insulating sapphire substrate has inferior thermalconductivity. Therefore, the insulating sapphire substrate may not serveas a next-generation white light source.

Different from the thick insulating sapphire substrate and the siliconcarbide substrate, a transparent conductive zinc oxide (“ZnO”) substratehas a small difference in a lattice constant relative to thenitride-based semiconductor while representing superior electrical andthermal conductivities and higher light transmittance. In addition, thetransparent ZnO substrate can be fabricated at an inexpensive cost.,Therefore, the transparent ZnO substrate has been recently spotlightedas a next-generation substrate for the nitride-based light emittingdevices. However, the surface of the transparent conductive zinc oxide(“ZnO”) substrate becomes unstable under a high temperature of 600° C.or more and a high vacuum of 10⁻³ torr or more, thus easily decomposingthe materials of the transparent conductive zinc oxide (ZnO) substrate.In addition, reduction of the transparent conductive ZnO substrate ispromoted in reducing ambient employment of ammonium (“NH₃”) and hydrogen(“H₂”). For this reason, the single-crystal nitride-based semiconductoris rarely grown under the reducing ambient having a temperature of 800°C. or more.

Other conductive substrates, including silicon (Si), silicon germanium(“SiGe”), or gallium arsenide (“GaAs”), have been suggested. However,these conductive substrates also represent problems at a temperature of500° C. or more due to the motion of the dislocation slip systemprovided in the conductive substrates, thereby causing strain to anddecomposition of materials. In addition, since these conductivesubstrates represent large differences in lattice constant and thermalexpansion coefficient relative to the nitride-based semiconductor,high-quality nitride-based layers may not be easily grown from the aboveconductive substrates.

A laser lift off (“LLO”) method has been most recently spotlighted inthe industrial field as a method of manufacturing a nitride-based lightemitting device for a next-generation high-brightness white lightsource. According to the LLO method, a high-quality nitride-basedsemiconductor layer or a light emitting structure is grown from an uppersurface of a sapphire substrate having inferior thermal and electricalconductivities, and then a strong energy laser beam is irradiated onto arear surface of the sapphire substrate, thereby separating the nitridesemiconductor layer and the light emitting structure from the sapphiresubstrate. A highly reliable nitride-based light emitting devicerepresenting high brightness and having a large size required for thenext-generation white light source can be manufactured by using the LLOmethod. However, since a strong energy laser beam is applied to thesapphire substrate in order to separate the nitride-based semiconductorlayer and the light emitting structure from the sapphire substrate, heathaving a temperature of 900° C. or more is generated from theinterfacial surface between the sapphire substrate and the nitride-basedsemiconductor layer/the light emitting structure, so that thenitride-based semiconductor layer may be damaged or deformed, loweringthe product yield and causing difficulties during the manufacturingprocess.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a single-crystal nitride-basedsemiconductor substrate and a method of manufacturing a vertical typenitride-based light emitting device by using the same. Moreparticularly, the present invention provides a method of growing asingle-crystal nitride-based semiconductor substrate under thehigh-temperature hydrogen atmosphere by using a seed material layer SMLand a multifunctional substrate MS, which are sequentially formed on anupper surface of a first substrate FS so as to prevent the upper surfaceof the first substrate including sapphire, silicon (Si), zinc oxide(ZnO) or gallium arsenide (GaAs) from being subject to mechanical andthermal strain and decomposition. The present invention also provides ahigh-quality nitride-based light emitting device and a manufacturingmethod thereof, in which the nitride-based light emitting device employsa single-crystal nitride-based semiconductor substrate and a lightemitting structure, so that the nitride-based light emitting device hasa large size and represents superior light efficiency and heatdissipation while being operated at a low operational voltage.

In one aspect of the present invention, a seed material layer SML isdeposited on a first substrate FS where organic residues including anatural oxide layer are removed from an upper surface of the firstsubstrate, and a multifunctional substrate MS is grown from the seedmaterial layer. A single-crystal nitride-based semiconductor layerincluding a nitride-based buffer layer is formed on the multifunctionalsubstrate MS. The seed material layer SML primarily assists the growthof the multifunctional substrate MS, which is essentially required forthe growth of the single-crystal nitride-based semiconductor substrateas well as for the fabrication of the highly reliable nitride-basedlight emitting device employing the single-crystal nitride-basedsemiconductor layer and the light emitting structure. In addition, theseed material layer SML improves the product yield of the nitride-basedlight emitting devices. In order to prevent the seed material layer SMLfrom being subjected to strain and decomposition under thehigh-temperature hydrogen atmosphere, the multifunctional substrate MSincludes aluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminumnitride oxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride(“B—N”), silicon carbide (“Si—C”), or silicon carbon nitride (“Si—C—N”).In addition, the multifunctional substrate MS has a single crystalstructure or a poly-crystal structure to grow the single-crystalnitride-based semiconductor layer having high quality. Thesingle-crystal nitride-based semiconductor substrate and the lightemitting device using the same can be used as a next-generation whitelight source having high capacity, large area, high brightness and highperformance.

According to an exemplary embodiment of the present invention, thesingle-crystal nitride-based semiconductor layer formed on themultifunctional substrate MS including aluminum oxide (“Al—O”), aluminumnitride (“Al—N”), aluminum nitride oxide (“Al—N—O”), gallium nitride(“Ga—N”), boron nitride (“B—N”), silicon carbide (“Si—C”), or siliconcarbon nitride (“Si—C—N”) serves to provide high-quality nitride-basedoptoelectronic devices and high-quality nitride-based flip chip typelight emitting devices. In particular, the nitride-based light emittingdevices include a nitride-based light emitting structure, wherein thenitride-based light emitting structure consists of a nitride-basedbuffer layer in the form of an amorphous layer, a poly-crystal layer ora single-crystal layer comprised of aluminum-indium-gallium-nitride(AlxInyGazN, wherein x, y and z are integers), an n-nitride-basedcladding layer comprised of aluminum-indium-gallium-nitride (AlxInyGazN,wherein x, y and z are integers), a p-nitride-based cladding layercomprised of aluminum-indium-gallium-nitride (AlxInyGazN, wherein x, yand z are integers) and a nitride-based active layer formed between twonitride-based cladding layers and comprised ofaluminum-indium-gallium-nitride (AlxInyGazN, wherein x, y and z areintegers).

The multifunctional substrate MS, which is a primary element of thepresent invention, includes at least one selected from the groupconsisting of aluminum oxide (“Al—O”), aluminum nitride (“Al—N”),aluminum nitride oxide (“Al—N—O”), gallium nitride (“Ga—N”), boronnitride (“B—N”), silicon carbide (“Si—C”) and silicon carbon nitride(“Si—C—N”). In addition, the multifunctional substrate MS has thermalstability and reduction-resistant characteristics under the reductionatmosphere where ammonium (“NH₃”) and hydrogen (“H₂”) carrier gas areprovided in the high temperature condition of about 1100° C. or more.Further, the multifunctional substrate MS allows the single-crystalnitride-based layer to be grown with a low density of dislocation thatexerts bad influence upon the electrical and electronic characteristicsof the optoelectronic device.

More preferably, the multifunctional substrate MS including aluminumoxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitride oxide(“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”), siliconcarbide (“Si—C”), or silicon carbon nitride (“Si—C—N”) is prepared inthe form of a single crystal layer or a poly-crystal layer having ahexagonal crystalline structure. However, the present invention is notlimited to the above crystal structure.

In exemplary embodiments, at least one of silicon (Si), germanium (Ge),indium (In), lithium (Li), gallium (Ga), magnesium (Mg), zinc (Zn),beryllium (Be), molybdenum (Mo), vanadium (V), copper (Cu), iridium(Ir), rhodium (Rh), ruthenium (Ru), tungsten (W), cobalt (Co), nickel(Ni), manganese (Mn), titanium (Ti), tantalum (Ta), chrome (Cr), andlanthanum (La) is added to the multifunctional substrate MS includingaluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitrideoxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”),silicon carbide (“Si—C”), or silicon carbon nitride (“Si—C—N”) in orderto adjust crystallinity and electron concentration and to reduce, asmuch as possible, dislocation density in the single-crystalnitride-based semiconductor layer formed on the upper surface of themultifunctional substrate MS. In exemplary embodiments, the metal, metaloxide, or metallic nitride oxide added to the multifunctional substrateMS has a nano-phase such that the dislocation density in thesingle-crystal nitride-based semiconductor layer can be easily adjusted.

In exemplary embodiments, the amount of elements added to themultifunctional substrate MS is limited within a range between 0.1weight percent to 49 weight percent.

In exemplary embodiments, the multifunctional substrate MS has athickness of 20 micron meters or less.

In exemplary embodiments, the multifunctional substrate MS includingaluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitrideoxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”),silicon carbide (“Si—C”), or silicon carbon nitride (“Si—C—N”) is formedthrough high-temperature/low temperature chemical vapor deposition(“CVD”) using chemical reaction and/or physical vapor deposition(“PVD”), wherein the CVD includes metal-organic chemical vapordeposition (“MOCVD”) and plasma enhanced vapor deposition (“PECVD”), andthe PVD includes thermal or E-beam evaporation, pulsed laser deposition,sputtering deposition employing gas ions, such as oxygen (O₂), nitrogen(N₂), or argon (Ar), and co-sputtering deposition using at least twosputtering guns.

More preferably, the multifunctional substrate MS is grown from theupper surface of the seed material layer SML, which is formed on theupper surface of the first substrate FS, within a temperature rangebetween room temperature and about 1500° C.

In order to successively grow the multifunctional substrate MS havingsuperior crystallinity, the seed material layer SML is primarily formedon the first substrate FS before the multifunctional substrate MS isformed on the first substrate FS.

The seed material layer SML is stacked on the upper surface of the firstsubstrate FS and allows the multifunctional substrate MS to havesuperior crystallinity and the hexagonal crystalline structure.

In exemplary embodiments, the seed material layer SML includes metal,oxide, nitride, carbide, boride, oxynitride, carbonnitride, or silicideas described below. In addition, the seed material layer SML is preparedin the form of a single layer or a multi-layer and has a thickness of 10microns or less.

Examples of the metal used for the seed material layer 110 include: Ti,Si, W, Co, Ni, Mo, Sc, Mg, Ge, Cu, Be, Zr, Fe, Al, Cr, Nb, Re, Rh, Ru,Hf, Ir, Os, V, Pd, Y, Ta, Tc, La and rare-earth metals.

Examples of the oxide used for the seed material layer 110 include: BeO,CeO₂, Cr₂O₃, HfO₂, La₂O₃, MgO, Nb₂O₃, SiO₂, Ta₂O₅, ThO₂, TiO₂, Y₂O₃,ZrO₂ and ZrSiO₂,

Examples of the nitride used for the seed material layer 110 include:AlN, GaN, InN, BN, Be₃N₂, Cr₂N, HfN, MoN, NbN, Si₃N₄, TaN, Ta₂N, Th₂N₂,TiN, WN₂, W₂N, VN and ZrN.

Examples of the carbide used for the seed material layer 110 include:B₄C, Cr₂, HfC, LaC₂, Mo₂C, Nb₂C, SiC, Ta₂C, ThC₂, TiC, W₂C, WC, V₂C andZrC,

Examples of the boride used for the seed material layer 110 include:AlB₂, BeB₂, CrB₂, HfB₂, LaB₂, MoB₂, MoB, NbB₄, SiB₆, TaB₂, ThB₄, TiB₂,WB, VB₂ and ZrB₂.

Examples of the oxynitride used for the seed material layer 110 includeAlON and SiON.

Examples of the carbonnitride used for the seed material layer 110include SiCN,

Examples of the silicide used for the seed material layer 110 include:CrSi₂, Cr₂Si, HfSi₂, MoSi₂, NbSi₂, TaSi₂, Ta₅Si₃, ThSi₂, Ti₅Si₃, WSi₂,W₅Si₃, V₃Si and ZrSi₂.

In exemplary embodiments, the seed material layer SML is formed throughhigh-temperature/low temperature chemical vapor deposition (“CVD”) usingchemical reaction and/or physical vapor deposition (“PVD”), wherein theCVD includes metal-organic chemical vapor deposition (“MOCVD”) andplasma enhanced vapor deposition (“PECVD”), and the PVD includes thermalor E-beam evaporation, pulsed laser deposition, sputtering depositionemploying gas ions, such as oxygen (O₂), nitrogen (N₂), or argon (Ar),and co-sputtering deposition using at least two sputtering guns.

More preferably, the seed material layer SML is deposited on the uppersurface of the first substrate within a temperature range between roomtemperature and about 1500° C.

In another exemplary embodiment of the present invention, a method ofgrowing the single-crystal nitride-based semiconductor substrateincludes;

depositing a seed material layer SML on an upper surface of a firstsubstrate FS including sapphire, silicon (Si), zinc oxide (“ZnO”) orgallium arsenide (“GaAs”) and growing a multifunctional substrate MSfrom an upper surface of the seed material layer SML;

forming a multi-layer on an upper surface of the multifunctionalsubstrate MS by MOCVD (metal-organic chemical vapor deposition), inwhich the multi-layer consists of a nitride-based buffer layer and athick single-crystal nitride-based layer stacked on the nitride-basedbuffer layer;

removing the seed material layer SML, and the first substrate FS byperforming wet etching or dry etching; and

performing a heat-treatment process in order to enhance crystallinity ofthe multifunctional substrate MS and the single-crystal nitride-basedlayer obtained through the above process.

In exemplary embodiments, further comprising forming a ZnO-based layerbetween the first substrate FS and the seed material layer SML, whereinthe ZnO-based layer is removed with the seed material layer SML and thefirst substrate FS.

In still another exemplary embodiment of the present invention, a methodof manufacturing a nitride-based light emitting device by using asingle-crystal nitride-based semiconductor substrate includes:

depositing a seed material layer SML on an upper surface of a firstsubstrate FS including sapphire, silicon (Si), zinc oxide (“ZnO”) orgallium arsenide (“GaAs”) and growing a multifunctional substrate MSfrom an upper surface of the seed material layer SML;

forming a multi-layer on an upper surface of the multifunctionalsubstrate MS by MOCVD, in which the multi-layer consists of anitride-based buffer layer, an n-nitride-based cladding layer, anitride-based active layer, and a p-nitride-based cladding layer, whichare sequentially stacked on the upper surface of the multifunctionalsubstrate MS;

removing the seed material layer SML, and the first substrate FS byperforming wet etching or dry etching;

performing a heat-treatment process in order to enhance crystallinity ofthe multifunctional substrate MS and the multi-layer obtained throughthe above process; and

selectively depositing reflective electrode materials or transparentelectrode materials on the multi-layer having the multifunctionalsubstrate MS and then performing an ohmic heat-treatment process.

In exemplary embodiments, further comprising forming a ZnO-based layerbetween the first substrate FS and the seed material layer SML, whereinthe ZnO-based layer is removed with the seed material layer SML and thefirst substrate FS.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the presentinvention will become readily apparent by reference to the followingdetailed description when considered in conjunction with theaccompanying drawings wherein:

FIGS. 1A and 1B are cross-sectional views showing a seed material layerin the form of a single layer or a bi-layer provided on an upper surfaceof a first substrate, a multifunctional substrate formed on the seedmaterial layer, and a single-crystal nitride-based layer (or a lightemitting structure for a light emitting device) formed on themultifunctional substrate for the purpose of homoepitaxial growth;

FIGS. 2A and 2B are cross-sectional views showing a ZnO-based layerformed on a first substrate, a seed material layer in the form of asingle layer or a bi-layer provided on an upper surface the ZnO-basedlayer, a multifunctional substrate formed on the seed material layer,and a single-crystal nitride-based layer (or a light emitting structurefor a light emitting device) formed on the multifunctional substrate forthe purpose of homoepitaxial growth;

FIG. 3 is a cross-sectional view showing a stacked structure in which aZnO-based layer and the seed material layer have been removed;

FIGS. 4A and 4B are a flowchart and a cross-sectional view showing avertical top emission type nitride-based light emitting devicefabricated by using a ZnO-based layer, a seed material layer and amultifunctional substrate according to an exemplary embodiment of thepresent invention;

FIGS. 5A and 5B are a flowchart and a cross-sectional view showing avertical flip chip type nitride-based light emitting device fabricatedby using a ZnO-based layer, a seed material layer and a multifunctionalsubstrate according to another exemplary embodiment of the presentinvention; and

FIGS. 6A and 6B are a flowchart and a cross-sectional view showing avertical top emission type nitride-based light emitting devicefabricated by using a ZnO-based layer, a seed material layer and amultifunctional substrate according to yet another exemplary embodimentof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. However, the present invention is not limited to the exemplaryembodiments illustrated hereinafter, and the exemplary embodimentsherein are rather introduced to provide easy and complete understandingof the scope and spirit of the present invention. Therefore, the presentinvention should not be construed as being limited to the exemplaryembodiments set forth herein. Like reference numerals in the drawingsdenote like elements.

The terminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting of thepresent invention. As used herein, the singular forms, “a”, “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “includes” and/or “including”, when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which the present invention belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, a method of manufacturing a single-crystal nitride-basedsemiconductor substrate by forming a ZnO-based layer, a seed materiallayer (“SML”) and a multifunctional substrate (“MS”) on an upper surfaceof a first substrate (“FS”) including sapphire, silicon (Si), zinc oxide(“ZnO”) or gallium arsenide (“GaAs”), and a method of manufacturing ahigh-quality nitride-based optoelectronic device by using thesingle-crystal nitride-based semiconductor substrate will be describedwith reference to the accompanying drawings.

FIGS. 1A and 1B are cross-sectional views showing a seed material layer(“SML”) in the form of a single layer or a bi-layer provided on an uppersurface a first substrate (“FS”), a multifunctional substrate (“MS”)formed on the seed material layer SML, and a single-crystalnitride-based layer (or a light emitting structure for a light emittingdevice) formed on the multifunctional substrate for the purpose ofhomoepitaxial growth.

Referring to FIG. 1A, a seed material layer 110 and a multifunctionalsubstrate 120 are sequentially formed on an upper surface of a firstsubstrate 100 including sapphire, silicon (Si), zinc oxide (“ZnO”) orgallium arsenide (“GaAs”). Then, a single-crystal nitride-based layer ora light emitting structure 130 is grown from the upper surface of themultifunctional substrate 120 in a metal organic vapor deposition(“MOCVD”) chamber under a hydrogen atmosphere where ammonium (“NH₃”) andhydrogen (“H₂”) carrier gas are provided in a high temperature conditionof 1000° C. or more.

The multifunctional substrate 120 is a primary element of the presentinvention and includes at least one selected from the group consistingof aluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitrideoxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”),silicon carbide (“Si—C”), and silicon carbon nitride (“Si—C—N”), whichhas thermal stability and reduction-resistant characteristics under thereduction atmosphere where ammonium (“NH₃”) and hydrogen (“H₂”) carriergas are provided in a high temperature condition of 1000° C. or more.

In exemplary embodiments, the multifunctional substrate 120 includingaluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitrideoxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”),silicon carbide (“Si—C”), or silicon carbon nitride (“Si—C—N”) isprepared in the form of a single crystal layer or a poly-crystal layerhaving a hexagonal crystalline structure. However, the present inventionis not limited to the above crystal structure.

In exemplary embodiments, oxide or nitride including at least one ofsilicon (Si), germanium (Ge), indium (In), lithium (Li), gallium (Ga),magnesium (Mg), zinc (Zn), beryllium (Be), molybdenum (Mo), vanadium(V), copper (Cu), iridium (Ir), rhodium (Rh), ruthenium (Ru), tungsten(W), cobalt (Co), nickel (Ni), manganese (Mn), titanium (Ti), tantalum(Ta), chrome (Cr), and lanthanum (La) is added to the multifunctionalsubstrate 120 including aluminum oxide (“Al—O”), aluminum nitride(“Al—N”), aluminum nitride oxide (“Al—N—O”), gallium nitride (“Ga—N”),boron nitride (“B—N”), silicon carbide (“Si—C”), or silicon carbonnitride (“Si—C—N”) in order to adjust crystallinity and electronconcentration and to reduce, as much as possible, dislocation density inthe single-crystal nitride-based semiconductor layer formed on the uppersurface of the multifunctional substrate 120. Preferably, metal oxide ornitride oxide added to the multifunctional substrate 120 has anano-phase such that the dislocation density in the single-crystalnitride-based semiconductor layer can be easily adjusted.

In exemplary embodiments, the amount of elements added to themultifunctional substrate 120 is limited within a range of about 0.1weight percent to about 49 weight percent.

In exemplary embodiments, the multifunctional substrate 120 has athickness of about 20 micron meters or less.

In exemplary embodiments, the multifunctional substrate 120 includingaluminum oxide (“Al—O”), aluminum nitride (“Al—N”), aluminum nitrideoxide (“Al—N—O”), gallium nitride (“Ga—N”), boron nitride (“B—N”),silicon carbide (“Si—C”), or silicon carbon nitride (“Si—C—N”) is formedthrough high-temperature/low temperature chemical vapor deposition(“CVD”) using chemical reaction and/or physical vapor deposition(“PVD”), wherein the CVD includes metal-organic chemical vapordeposition (“MOCVD”) and plasma enhanced chemical vapor deposition(“PECVD”), and the PVD includes thermal or E-beam evaporation, pulsedlaser deposition, sputtering deposition employing gas ions, such asoxygen (O₂), nitrogen (N₂), or argon (Ar), and co-sputtering depositionusing at least two sputtering guns.

More preferably, the multifunctional substrate 120 is grown from theupper surface of the seed material layer 110, which is formed on theupper surface of the first substrate 100, within a temperature rangebetween room temperature and 1500° C.

In order to successively grow the multifunctional substrate 120 havingsuperior crystallinity, the seed material layer 110 is primarily formedon the first substrate 100 before the multifunctional substrate 120 isformed on the first substrate 100.

The seed material layer 110 is stacked on the upper surface of the firstsubstrate 100 and allows the multifunctional substrate 120 to havesuperior crystallinity and a hexagonal crystalline structure.

In exemplary embodiments, the seed material layer 110 includes metal,oxide, nitride, carbide, boride, oxynitride, carbonnitride, or silicideas described below. In addition, the seed material layer 110 is preparedin the form of a single layer or a multi-layer having a thickness of 10microns or less.

Examples of the metal used for the seed material layer 110 include: Ti,Si, W, Co, Ni, Mo, Sc, Mg, Ge, Cu, Be, Zr, Fe, Al, Cr, Nb, Re, Rh, Ru,Hf, Ir, Os, V, Pd, Y, Ta, Tc, La and rare-earth metals.

Examples of the oxide used for the seed material layer 110 include: BeO,CeO₂, Cr₂O₃, HfO₂, La₂O₃, MgO, Nb₂O₃, SiO₂, Ta₂O₅, ThO₂, TiO₂, Y₂O₃,ZrO₂ and ZrSiO₂,

Examples of the nitride used for the seed material layer 110 include:AlN, GaN, InN, BN, Be₃N₂, Cr₂N, HfN, MoN, NbN, Si₃N₄, TaN, Ta₂N, Th₂N₂,TiN, WN₂, W₂N, VN and ZrN.

Examples of the carbide used for the seed material layer 110 include:B₄C, Cr₂, HfC, LaC₂, Mo₂C, Nb₂C, SiC, Ta₂C, ThC₂, TiC, W₂C, WC, V₂C andZrC,

Examples of the boride used for the seed material layer 110 include:AlB₂, BeB₂, CrB₂, HfB₂, LaB₂, MoB₂, MoB, NbB₄, SiB₆, TaB₂, ThB₄, TiB₂,WB, VB₂ and ZrB₂.

Examples of the oxynitride used for the seed material layer 110 includeAlON and SiON.

Examples of the carbonnitride used for the seed material layer 110include SiCN,

Examples of the silicide used for the seed material layer 110 include:CrSi₂, Cr₂Si, HfSi₂, MoSi₂, NbSi₂, TaSi₂, Ta₅Si₃, ThSi₂, Ti₅Si₃, WSi₂,W₅Si₃, V₃Si and ZrSi₂.

In exemplary embodiments, the seed material layer 110 is formed throughhigh-temperature/low temperature chemical vapor deposition (“CVD”) usingchemical reaction and/or physical vapor deposition (“PVD”), wherein theCVD includes metal-organic chemical vapor deposition (“MOCVD”) andplasma enhanced chemical vapor deposition (“PECVD”). The PVD includesthermal or E-beam evaporation, pulsed laser deposition, sputteringdeposition employing gas ions, such as oxygen (O₂), nitrogen (N₂), orargon (Ar), and co-sputtering deposition using at least two sputteringguns.

More preferably, the seed material layer 110 is deposited on the uppersurface of the first substrate 100 within a temperature range betweenroom temperature and 1500° C.

According to another exemplary embodiment of the present invention,instead of a single seed material layer 110 shown in FIG. 1A, first andsecond seed material layers 110 a and 110 b are formed on the firstsubstrate 100 including sapphire, silicon (Si), zinc oxide (“ZnO”) orgallium arsenide (“GaAs”). In this case, the multifunctional substrate120 is grown from the upper surface of the second seed material layer110 b and the single-crystal nitride-based layer or the light emittingstructure 130 is stacked on the multifunctional substrate 120.

If the seed material layer is prepared in the form of a bi-layerstructure as shown in FIG. 1B, the quality of the multifunctionalsubstrate 120 can be improved, thus improving the quality of thesingle-crystal nitride-based layer or the light emitting structure 130.

In exemplary embodiments, the first seed material layer 110 a includes amaterial different from that of the second seed material layer 110 b.

FIGS. 2A and 2B are cross-sectional views showing a ZnO-based layer 240formed on a first substrate 200, a seed material layer 210 in the formof a single layer (FIG. 2A) or a bi-layer (FIG. 2B) provided on theupper surface the ZnO-based layer 240, a multifunctional substrate 220formed on the seed material layer 210, and a single-crystalnitride-based layer 230 (or a light emitting structure for a lightemitting device) formed on the multifunctional substrate 220 for thepurpose of homoepitaxial growth.

Referring to FIGS. 2A and 2B, after growing the single-crystalnitride-based layer or the light emitting structure 230 by using theseed material layer 210 in the form of a single layer or a bi-layer andthe multifunctional substrate 220, the ZnO-based layer 240, which iseasily dissolved by means of acid and base solution, is formed on theupper surface of the first substrate 200 before the seed material layer210 is deposited on the upper surface of the first substrate 200 in sucha manner that the thick first substrate 200 can be readily removedthrough wet etching or dry etching without causing any etching damage tothe single-crystal nitride-based layer or the light emitting structure230.

At least one of silicon (Si), germanium (Ge), indium (In), lithium (Li),gallium (Ga), magnesium (Mg), zinc (Zn), beryllium (Be), molybdenum(Mo), vanadium (V), copper (Cu), iridium (Ir), rhodium (Rh), ruthenium(Ru), tungsten (W), cobalt (Co), nickel (Ni), manganese (Mn), titanium(Ti), tantalum (Ta), chrome (Cr), and lanthanum (La) is added to theZnO-based layer 240.

In exemplary embodiments, the amount of elements added to the ZnO-basedlayer 240 is limited within a range of about 0.1 weight percent to about49 weight percent.

In exemplary embodiments, the ZnO-based layer 240 is formed throughhigh-temperature/low temperature chemical vapor deposition (“CVD”) usingchemical reaction and/or physical vapor deposition (“PVD”), wherein theCVD includes metal-organic chemical vapor deposition (“MOCVD”) andplasma enhanced chemical vapor deposition (“PECVD”). The PVD includesthermal or E-beam evaporation, pulsed laser deposition, sputteringdeposition employing gas ions, such as oxygen (O₂), nitrogen (N₂), orargon (Ar), and co-sputtering deposition using at least two sputteringguns.

More preferably, the ZnO-based layer 240 is grown from the upper surfaceof the first substrate 200 within a temperature range between roomtemperature and 1500° C.

FIG. 3 is a cross-sectional view showing a stacked structure in whichthe ZnO-based layer and the seed material layer SML have been removed.

Referring to FIG. 3, the thick first substrate 100 or 200, the ZnO-basedlayer 240, and the seed material layer 110 or 210 are completely removedfrom the stack structure shown in FIGS. 1 and 2 through performing wetetching by using acid solution or base solution or performing dryetching by using gas ions, such as hydrogen ions. The single-crystalnitride-based layer or the light emitting structure 330 for the lightemitting device is stacked on the upper surface of the multifunctionalsubstrate 320 for the purpose of homoepitaxial growth.

In exemplary embodiments, in order to improve crystallinity orelectrical characteristics of the single-crystal nitride-based layer orthe light emitting structure 330 stacked on the upper surface of themultifunctional substrate 320 for the purpose of homoepitaxial growth, aheat-treatment process is performed within a temperature range betweenroom temperature and 1500° C. under oxygen (O₂), nitrogen (N₂), hydrogen(H₂), argon (Ar), vacuum or air atmosphere.

FIG. 4A is a flowchart showing the procedure of manufacturing a verticaltop emission type nitride-based light emitting device. FIG. 4B is across-sectional view showing the vertical top emission typenitride-based light emitting device including a ZnO-based layer, a seedmaterial layer SML, and a multifunctional substrate MS according to anexemplary embodiment of the present invention.

Referring to FIGS. 4A and 4B, similar to FIGS. 3A and 3B, anitride-based buffer layer 420 and a nitride-based light emittingstructure, which includes an n-nitride-based cladding layer 430, anitride-based active layer 440 and a p-nitride-based cladding layer 450,are sequentially formed on the upper surface of a multifunctionalsubstrate 410 at blocks 405, 415, 425, 435 and 445. A second supportingsubstrate is attached to an upper portion of a p-nitride-basedsemiconductor layer so as to prevent the light emitting structure frombeing dissolved during the manufacturing process for the nitride-basedlight emitting device at block 455. Then, lithography and etchingprocesses are performed so as to form patterns having various sizes andintervals in the multifunctional substrate 410 at blocks 465 and 475. Inthis state, a reflective n-ohmic contact layer 480 is formed in themultifunctional substrate 410 at block 485 and a metallic reflector 490is deposited on the bottom surface of the multifunctional substrate 410at block 495. Thereafter, the second supporting substrate attached tothe upper portion of the p-nitride-based semiconductor is removed and atransparent p-ohmic contact layer 460 is formed on the p-nitride-basedcladding layer 450 at block 505, thereby obtaining the vertical topemission type nitride-based light emitting device.

The procedure of manufacturing the high-quality light emitting device byusing the single-crystal nitride-based semiconductor substrate accordingto the present invention may not be limited to the procedure shown inFIG. 4A. In other words, the procedure shown in FIG. 4A can be modifiedin combination with technologies suitable to fabricate the highlyreliable light emitting device used as a next-generation white lightsource.

According to another exemplary embodiment of the present invention, theseed material layer SML including chrome oxide (“Cr₂O₃”) is deposited onthe upper surface of the first substrate FS including sapphire, silicon(Si), silicon germanium (“SiGe”), zinc oxide (“ZnO”) or gallium arsenide(“GaAs”), and the multifunctional substrate MS 410 includingsingle-crystal aluminum oxide (Al₂O₃) is grown from the upper surface ofthe seed material layer SML. In this state, the nitride-based bufferlayer 420 and the single-crystal nitride-based light emitting structure,which includes the n-nitride-based cladding layer 430, the nitride-basedactive layer 440 and the p-nitride-based cladding layer 450, aresequentially stacked on the multifunctional substrate MS, therebyobtaining the vertical top emission type nitride-based light emittingdevice according to the present invention.

In general, each of the nitride-based buffer layer 420, then-nitride-based cladding layer 430, the nitride-based active layer 440and the p-nitride-based cladding layer 450 basically include a compoundselected from Group III nitride-based compounds expressed as AlxInyGazN(where x, y and z are integers). In addition, dopant is added to then-nitride-based cladding layer 430 and the p-nitride-based claddinglayer 450.

The nitride-based active layer 440 can be prepared in the form of asingle layer or a multiple quantum well (“MQW”), that is, a bi-layersuch as an AlxInyGazN/AlxInyGazN layer (where x, y and z are integers).

If a GaN-based compound is used to fabricate the nitride-based lightemitting device, the nitride-based buffer layer 420 is formed by usingGaN, the n-nitride-based cladding layer 430 is formed by addingn-dopant, such as silicon (Si), germanium (Ge), selenium (Se) ortellurium (Te), to GaN, the nitride-based active layer 440 is preparedin the form of InGaN/GaN MQW or AlGaN/GaN MQW. The p-nitride-basedcladding layer 450 is formed by adding p-dopant, such as magnesium (Mg),zinc (Zn), calcium (Ca), strontium (St) or barium (Ba), to GaN.

The reflective n-ohmic contact layer 480 is interposed between then-nitride-based cladding layer 430 and the metallic reflector 490. Thereflective n-ohmic contact layer 480 may have various structuresgenerally known in the art, such as an aluminum/titanium (Al/Ti) layerhaving a large thickness. In exemplary embodiments, the metallicreflector 490 includes a thick reflective metal, such as aluminum (Al),silver (Ag) or rhodium (Rh).

The transparent p-ohmic contact layer 460 includes electrode materialsused to form a p-ohmic contact. The electrode materials include oxidizednickel-gold (“Ni—Au”), oxidized silver (Ag), transparent conductingoxides, which are oxide compounds based on indium tin oxide (“ITO”),zinc oxide (“ZnO”), tin oxide (“SnO₂”), or indium oxide (“In₂O₃”), andconducting transitional metal nitrides including tin nitrides (“TiN”).In addition, a p-electrode pad 470 has a stacked layer structure, suchas a nickel/gold (“Ni/Au”) layer or a silver/gold (Ag/Au) layer.

The above layers can be formed through conventional deposition methods,such as E-beam evaporation, physical vapor deposition (“PVD”), chemicalvapor deposition (“CVD”), plasma laser deposition (“PLD”), dual-typethermal evaporation, orsputtering.

FIG. 5A is a flowchart showing a procedure of manufacturing a verticalflip chip type nitride-based light emitting device. FIG. 5B is across-sectional view showing the vertical flip chip type nitride-basedlight emitting device including a ZnO-based layer, a seed material layerSML and a multifunctional substrate according to an exemplary embodimentof the present invention.

Referring to FIGS. 5A and 5B, similar to FIGS. 3A and 3B, anitride-based buffer layer 520 and a nitride-based light emittingstructure, which includes an n-nitride-based cladding layer 530, anitride-based active layer 540 and a p-nitride-based cladding layer 550,are sequentially formed on the upper surface of a multifunctionalsubstrate 510 at blocks 515, 525, 535, 545 and 555. After that, a secondsupporting substrate is attached to an upper portion of ap-nitride-based semiconductor layer so as to prevent the light emittingstructure from being dissolved during the manufacturing process for thenitride-based light emitting device at block 565. Then, lithography andetching processes are performed so as to form patterns having varioussizes and intervals in the multifunctional substrate 510 at blocks 575and 585. In this state, a transparent n-ohmic contact layer 580 isformed in the multifunctional substrate 510 at block 595 and atransparent conducting layer 490 is deposited on the bottom surface ofthe multifunctional substrate 510 at block 605. Thereafter, the secondsupporting substrate attached to the upper portion of thep-nitride-based semiconductor is removed at block 615 and a reflectivep-ohmic contact layer 560 is formed on the p-nitride-based claddinglayer 550 at block 625, thereby obtaining the vertical flip chip typenitride-based light emitting device.

The procedure of manufacturing the high-quality light emitting device byusing the single-crystal nitride-based semiconductor substrate accordingto the present invention may not be limited to the procedure shown inFIG. 5A. In other words, the procedure shown in FIG. 5A can be modifiedin combination with technologies suitable to fabricate the highlyreliable light emitting device used as a next-generation white lightsource.

According to an exemplary embodiment of the present invention, the seedmaterial layer SML including zinc oxide (“ZnO”) or molybdenum (Mo) isdeposited on the upper surface of the first substrate FS includingsapphire, silicon (Si), silicon germanium (“SiGe”), zinc oxide (“ZnO”)or gallium arsenide (“GaAs”), and the multifunctional substrate MSincluding single-crystal aluminum oxide (“Al₂O₃”) is grown from theupper surface of the seed material layer SML. In this state, thenitride-based buffer layer 520 and the single-crystal nitride-basedlight emitting structure, which includes the n-nitride-based claddinglayer 430, the nitride-based active layer 440 and the p-nitride-basedcladding layer 450, are sequentially stacked on the multifunctionalsubstrate MS, thereby obtaining the vertical flip chip typenitride-based light emitting device according to the present invention.

In general, each of the nitride-based buffer layer 520, then-nitride-based cladding layer 530, the nitride-based active layer 540and the p-nitride-based cladding layer 550 basically include a compoundselected from Group III nitride-based compounds expressed as AlxInyGazN(where x, y and z are integers). In addition, dopant is added to then-nitride-based cladding layer 530 and the p-nitride-based claddinglayer 550.

The nitride-based active layer 540 can be prepared in the form of asingle layer or a multiple quantum well (“MQW”), that is, a bi-layersuch as an AlxInyGazN/AlxInyGazN layer (where x, y and z are integers).

If a GaN-based compound is used to fabricate the nitride-based lightemitting device, the nitride-based buffer layer 520 is formed by usingGaN, the n-nitride-based cladding layer 530 is formed by addingn-dopant, such as silicon (Si), germanium (Ge), selenium (Se) ortellurium (Te), to GaN, the nitride-based active layer 540 is preparedin the form of InGaN/GaN MQW or AlGaN/GaN MQW. The p-nitride-basedcladding layer 550 is formed by adding p-dopant, such as magnesium (Mg),zinc (Zn), calcium (Ca), strontium (St) or barium (Ba), to GaN.

The transparent n-ohmic contact layer 580 is interposed between then-nitride-based cladding layer 530 and the transparent conducting layer590. The transparent n-ohmic contact layer 580 includes electrodematerials used to form a p-ohmic contact. The electrode materialsinclude transparent conducting oxides, which are oxide compounds basedon indium tin oxide (“ITO”), zinc oxide (“ZnO”), tin oxide (“SnO₂”), orindium oxide (“In₂O₃”), and conducting transitional metal nitridesincluding tin nitrides (“TiN”). In addition, the transparent conductinglayer 590 is formed by using conducting transitional metal nitridesincluding tin nitrides (“TiN”) or transparent conducting oxides, whichare oxide compounds based on indium tin oxide (“ITO”), zinc oxide(“ZnO”), tin oxide (“SnO₂”), or indium oxide (“In₂O₃”).

The reflective p-ohmic contact layer 560 includes electrode materialsused to form a reflective p-ohmic contact, such as aluminum (Al), silver(Ag) or rhodium (Rh), which is generally known in the art. In addition,a p-electrode pad 570 has a stacked layer structure, such as anickel/gold (“Ni/Au”) layer or a silver/gold (“Ag/Au”) layer.

The above layers can be formed through conventional deposition methods,such as E-beam evaporation, physical vapor deposition (“PVD”), chemicalvapor deposition (“CVD”), plasma laser deposition (“PLD”), dual-typethermal evaporation, or sputtering.

FIG. 6A is a flowchart showing a procedure of manufacturing a verticaltop emission type nitride-based light emitting device. FIG. 6B is across-sectional view showing the vertical top emission typenitride-based light emitting device including a ZnO-based layer, a seedmaterial layer SML and a multifunctional substrate according to anotherexemplary embodiment of the present invention.

Referring to FIGS. 6A and 6B, similar to FIGS. 3A and 3B, anitride-based buffer layer and a nitride-based light emitting structure,which includes an n-nitride-based cladding layer 650, a nitride-basedactive layer 640 and a p-nitride-based cladding layer 630, aresequentially formed on the upper surface of a multifunctional substrateMS at blocks 635, 645, 655, 665 and 675. After that, a second supportingsubstrate is attached to an upper portion of a p-nitride-basedsemiconductor layer at block 685 to prevent the light emitting structurefrom being dissolved during the manufacturing process for thenitride-based light emitting device. Then, the multifunctional substrateMS is completely removed through the wet etching process or the dryetching process at blocks 695 and 705, and a reflective bonding p-ohmiccontact layer 620 (e.g., third supporting substrate) is bonded to afirst supporting substrate 610 by means of a bonding material at block715. Thereafter, the second supporting substrate attached to the upperportion of the p-nitride-based semiconductor is removed at block 725 anda transparent n-ohmic contact layer 660 is formed on the n-nitride-basedcladding layer 650 at block 735, thereby obtaining the vertical topemission type nitride-based light emitting device.

The procedure of manufacturing the high-quality light emitting device byusing the single-crystal nitride-based semiconductor substrate accordingto the present invention may not be limited to the procedure shown inFIG. 6A. In other words, the procedure shown in FIG. 6A can be modifiedin combination with technologies suitable to fabricate the highlyreliable light emitting device used as a next-generation white lightsource.

According to the exemplary embodiment of the present invention, the seedmaterial layer SML including zinc oxide (“ZnO”) or titanium (Ti) isdeposited on the upper surface of the first substrate FS includingsapphire, silicon (Si), silicon germanium (“SiGe”), zinc oxide (“ZnO”)or gallium arsenide (“GaAs”), and the multifunctional substrate MSincluding single-crystal aluminum oxide (“Al₂O₃”) is grown from theupper surface of the seed material layer SML. In this state, thenitride-based buffer layer and the single-crystal nitride-based lightemitting structure, which includes the n-nitride-based cladding layer650, the nitride-based active layer 640 and the p-nitride-based claddinglayer 630, are sequentially stacked on the multifunctional substrate MS620, thereby obtaining the vertical top emission type nitride-basedlight emitting device according to the present invention.

In general, each of the nitride-based buffer layer, the n-nitride-basedcladding layer 650, the nitride-based active layer 640 and thep-nitride-based cladding layer 630 basically include a compound selectedfrom Group III nitride-based compounds expressed as AlxInyGazN (where x,y and z are integers). In addition, dopant is added to then-nitride-based cladding layer 650 and the p-nitride-based claddinglayer 630.

The nitride-based active layer 640 can be prepared in the form of asingle layer or a multiple quantum well (“MQW”), that is, a bi-layersuch as an AlxInyGazN/AlxInyGazN layer (where x, y and z are integers).

If a GaN-based compound is used to fabricate the nitride-based lightemitting device, the nitride-based buffer layer is formed by using GaN,the n-nitride-based cladding layer 650 is formed by adding n-dopant,such as silicon (Si), germanium (Ge), selenium (Se) or tellurium (Te),to GaN, the nitride-based active layer 640 is prepared in the form ofInGaN/GaN MQW or AlGaN/GaN MQW, and the p-nitride-based cladding layer630 is formed by adding p-dopant, such as magnesium (Mg), zinc (Zn),calcium (Ca), strontium (St) or barium (Ba), to GaN.

The transparent n-ohmic contact layer 660 is interposed between then-nitride-based cladding layer 650 and a reflective n-electrode pad 670.The transparent n-ohmic contact layer 660 includes electrode materialsused to form a p-ohmic contact. The electrode materials includetransparent conducting oxides, which are oxide compounds based on indiumtin oxide (“ITO”), zinc oxide (“ZnO”), tin oxide (“SnO₂”), or indiumoxide (“In₂O₃”), and conducting transitional metal nitrides includingtin nitrides (“TiN”). In addition, the reflective n-electrode pad 670has a stacked layer structure, such as a nickel/gold (“Ni/Au”) layer ora silver/gold (“Ag/Au”) layer. The reflective bonding p-ohmic contactlayer 620 can be formed with various structures having a large thicknessby using a solid solution or a reflective metal, such as silver (Ag) orrhodium (Rh).

The above layers can be formed through conventional deposition methods,such as E-beam evaporation, physical vapor deposition (“PVD”), chemicalvapor deposition (“CVD”), plasma laser deposition (“PLD”), dual-typethermal evaporation, orsputtering.

As described above, the present invention provides a single-crystalnitride-based semiconductor substrate and a method of manufacturing avertical type nitride-based light emitting device by using the same.According to the present invention, a single-crystal nitride-basedsemiconductor substrate or a light emitting structure for homoepitaxialgrowth can be formed under high temperature and hydrogen atmosphere byusing a seed material layer SML and a multifunctional substrate MS,which are sequentially formed on an upper surface of a first substrateFS so as to prevent mechanical and thermal strain and decomposition fromoccurring at the upper surface of the first substrate FS includingsapphire, silicon (Si), zinc oxide (“ZnO”) or gallium arsenide (“GaAs”).Thus, the present invention provides a high-quality nitride-based lightemitting device representing superior light efficiency and heatdissipation while being operated at a low operational voltage.

Although the exemplary embodiments of the present invention have beendescribed, it is understood that the present invention should not belimited to these exemplary embodiments but various changes andmodifications can be made by one ordinary skilled in the art within thespirit and scope of the present invention as hereinafter claimed.

1. A method of growing a single-crystal nitride-based semiconductorsubstrate, the method comprising: depositing a seed material layer on anupper surface of a first substrate and growing a multifunctionalsubstrate from an upper surface of the seed material layer; forming amulti-layer on an upper surface of the multifunctional substrate by(metal-organic chemical vapor deposition) MOCVD, in which themulti-layer consists of a nitride-based buffer layer and asingle-crystal nitride-based layer stacked on the nitride-based bufferlayer; removing the seed material layer, and the first substrate byperforming wet etching or dry etching; and performing a heat-treatmentprocess in order to enhance crystallinity of the multifunctionalsubstrate and the single-crystal nitride-based layer obtained throughthe above steps.
 2. The method of claim 1, wherein the first substrateincludes sapphire, silicon (Si), zinc oxide (ZnO) or gallium arsenide(GaAs).
 3. The method of claim 1, further comprising forming a ZnO-basedlayer between the first substrate and the seed material layer, whereinthe ZnO-based layer is removed with the seed material layer and thefirst substrate.
 4. The method of claim 1, wherein the heat-treatment isperformed at a temperature of 1500° C. or less under oxygen (O₂),nitrogen (N₂), hydrogen (H₂), argon (Ar), or air atmosphere.
 5. Themethod of claim 1, wherein a sequence of a manufacturing procedure forthe nitride-based light emitting device is changeable.
 6. A method ofmanufacturing a nitride-based light emitting device, the methodcomprising: depositing a seed material layer on an upper surface of afirst substrate and growing a multifunctional substrate from an uppersurface of the seed material layer; forming a multi-layer on an uppersurface of the multifunctional substrate by (metal-organic chemicalvapor deposition) MOCVD, in which the multi-layer consists of anitride-based buffer layer, and a single-crystal nitride-based layerincluding an n-nitride-based cladding layer a nitride-based activelayer, and a p-nitride-based cladding layer, which are sequentiallystacked on the upper surface of the multifunctional substrate; removingthe seed material layer, and the first substrate by performing wetetching or dry etching; performing a heat-treatment process in order toenhance crystallinity of the multifunctional substrate and themulti-layer obtained through the above steps; and selectively depositingreflective electrode materials or transparent electrode materials on themulti-layer having the multifunctional substrate and then performing anohmic heat-treatment process.
 7. The method of claim 6, wherein thefirst substrate includes sapphire, silicon (Si), zinc oxide (ZnO) orgallium arsenide (GaAs).
 8. The method of claim 6, further comprisingforming a ZnO-based layer between the first substrate and the seedmaterial layer, wherein the ZnO-based layer is removed with the seedmaterial layer and the first substrate.
 9. The method of claim 6,wherein the heat-treatment is performed at a temperature of 1500° C. orless under oxygen (O₂), nitrogen (N₂), hydrogen (H₂), argon (Ar), or airatmosphere.
 10. The method of claim 6, wherein a sequence of amanufacturing procedure for the nitride-based light emitting device ischangeable.